Clematis species- Gantok

Please help with Id_02 : 2 posts by 2 authors. Attachments (2)
Another amazing flowering on a hanging pot, in the roof garden of Gantok hotel.
Flowers are of 4 inches diameter, non fragrant. Creeper like plant. The violet-blue colour and the size of the flower dumbfounded me.
Seen in May 2015.
Please help with id .
Also seek advice on whether Kolkata climate will be suitable for it's flowering and how can I get it.
This is a Clematis sp.
I think you can very well grow this at your place...